Question

我继承了一个包含＆＃34;重复问题＆＃34;。

的数据库

我跑的时候：

SELECT myFIELD，COUNT（*）c from myTABLE GROUP by myFIELD HAVING c＆gt; 1;

我得到了600条重复的记录

无或三倍或任何其他多重

我希望杀掉其中一条记录，让我没有重复。

查询是什么样的？

Answer 1

您可以使用这样的查询...您应该根据同一行重复的次数重复查询。

delete from my_table 
where (myFIELD, id) in  
(select a.myFIELD, max(a.id) 
FROM myTABLE as a  GROUP BY a.myFIELD HAVING count(*) > 1)

否则你可以使用

delete from my_table 
where (myFIELD, id) not in 
(select a.myFIELD, min(a.id) 
FROM myTABLE as a GROUP BY a.myFIELD )

这应删除镜头中的所有重复行

如果表名有问题

delete from my_table 
where (myFIELD, id) in  (select field, id from 
(select a.myFIELD as field, max(a.id) as  id
FROM myTABLE as a  GROUP BY a.myFIELD HAVING count(*) > 1) as t)

在MySql中删除重复项

1 个答案: